// g++ pointer2.cpp -o pointer2
#include <iostream>
struct pointer2
{
    int a=1;
    float b=2;
    int c=3;
};

pointer2 a{2,3,4} ;// init value
pointer2 *a_ptr=&a;
int main(){
    a_ptr->b = 4;
    std::cout<<a.a<<a.b<<a.c<<std::endl;
}